Login Sign in
Login Sign in

Join thousands of pet parents and get vet-approved guidance, product reviews, exclusive deals, and more!

Cat Allergy Medicine: 6 Vet-Prescribed Products to Stop the Itch

Woman giving cat allergy medicine
Skip To

Do you suffer from allergies? If so, you’re probably familiar with the misery of congestion, sneezing, and watery eyes after spending time outdoors on a spring day or cuddling extra-close with your pet. This allergic response may leave you reaching for a variety of allergy medications, including prescription and over-the-counter treatments, in an effort to control your discomfort.

What about cats, though? We know cats can trigger allergies in people, but can cats be allergic to substances in their own environment? And, if so, can cat allergy medicine treat these allergies? Read on to learn more.

Featured Cat Allergy Medications

Do Cats Get Allergies?

Just like humans, cats can suffer from allergies. However, feline allergies don’t always look like ours. While humans tend to develop sniffling, sneezing, and watery eyes, cats with allergies are more likely to stand out because of their hair loss and itchy, inflamed skin.

Allergies in cats often fall into one of three categories:

Flea allergies: While flea bites can be a nuisance for any animal, some cats are allergic to proteins that are found in a flea’s saliva. These cats may experience extreme itching and skin inflammation following just a single flea bite.

Food allergies: While less common than flea allergies, food allergies can play a role in some cases of feline skin disease. Cats may develop allergies to any protein source in their food, including beef, chicken, pork, eggs, dairy, or fish. These cats will experience skin inflammation when they eat food that contains this protein.

Environmental allergies: Dust, pollen, and other environmental allergens can cause allergies in cats, just like they do in their human counterparts. When these allergens are inhaled, an allergic response can lead to redness of the skin, itching, and hair loss.

The signs of flea allergies, environmental allergies, and food allergies can be nearly identical. Therefore, in most cases, a veterinary examination and further testing will be needed to determine the cause of your cat’s allergies.  

Why Your Vets Recommend Prescription Cat Allergy Medications

If your veterinarian is able to identify the cause of your cat’s allergies, you might be able to successfully avoid that allergen. Flea allergies can be managed through the appropriate and consistent use of prescription flea prevention, while food allergies can be managed through the use of a hypoallergenic diet.

In many cases, however, feline allergies are caused by environmental allergens. It is often unrealistic to avoid dust, pollen, mold, and other inhaled allergens for the rest of your cat’s life, just like it’s not always possible for humans to avoid these allergens. Therefore, veterinarians often recommend medicine for cats with allergies. These medications do not cure a cat’s allergies, but they can reduce the signs of allergies and help an allergic cat experience a better quality of life.

6 Prescription Cat Allergy Medications Trusted By Vets

While there are many medications that may benefit cats with allergies, veterinarians tend to reach for certain medications due to their proven track record of safety and efficacy.

The right cat allergy medicine for your feline will depend on the severity of your pet’s allergies and any other concurrent medical conditions that must be managed. In some cases, trial-and-error is required to determine the best allergy medicine for your cat.  

The following six medications are commonly used to treat allergies in cats.


This allergy medicine for cats contains diphenhydramine, the same antihistamine that is found in Benadryl (a human medication). However, in this medication, diphenhydramine is contained in the small amounts that are needed for safe feline dosing. Diphenhydramine works by counteracting histamine, an inflammatory signal that is released by the body during an allergic reaction. By counteracting the effects of histamine, diphenhydramine can reduce the signs of allergies. The primary side effect associated with diphenhydramine is sedation.

Atopica for Cats

Atopica (cyclosporine) is a cat allergy treatment that was developed to give the benefits of corticosteroids, without the associated risks. In fact, it’s the first FDA-approved nonsteroid medication to treat allergic skin disease in cats. This medication targets the allergic response, without affecting a cat’s immune system. Atopica is often more effective than antihistamines, like Vetadryl, and it comes in an oral solution that may be easier to dose than pills or tablets. The most common side effects of Atopica for cats include vomiting and diarrhea.


Cyclosporine is a generic equivalent to Atopica. It theoretically has the same benefits and side effects as Atopica, at a lower cost. Cyclosporine is usually available in the form of capsules, but it can be compounded into an oral solution if desired. Talk to your veterinarian to decide whether Atopica or generic cyclosporine is the right fit for your cat. 


Hydroxyzine, like diphenhydramine, is an antihistamine. Unlike diphenhydramine, however, hydroxyzine is available only with a veterinarian’s prescription. Hydroxyzine tends to have stronger effects than diphenhydramine. It may be more effective in the treatment of allergies than diphenhydramine, but it may also cause more sedation.


Prednisone and prednisolone are closely related drugs, belonging to a class of drugs known as corticosteroids. While antihistamines target histamine, corticosteroids reduce the body’s overall inflammatory/immune response. Corticosteroids are often much more effective than antihistamines for treating allergies, but they also carry a greater risk of side effects. Side effects of prednisone and prednisolone include increased thirst and urination, weight gain, restlessness, and a weakened immune system.  


Dexamethasone is another corticosteroid that may be used to treat allergies in cats. It is stronger than prednisone and prednisolone, which means that lower doses can be used. However, dexamethasone is associated with similar side effects, and it is also associated with an increased risk of diabetes. Your veterinarian will select the best corticosteroid for your cat, to control their signs of allergies while minimizing the risk of side effects.

Tips and Safety for Using Cat Allergy Medications

Talk to your veterinarian before giving any medication to your cat. Allergy pills for cats can have harmful effects when used incorrectly or when given at improper dosages. Your veterinarian will select the best allergy medication and the best dosage for your cat. Do not make any dosage changes without speaking to your veterinarian.  

Also, it is important not to combine medications without your veterinarian’s approval. Combining multiple immunosuppressive drugs (such as prednisone and cyclosporine) could increase your cat’s risk of infection. Combining multiple antihistamines (such as diphenhydramine and hydroxyzine) could cause serious sedation. Be sure that your veterinarian is familiar with any medications your cat is taking, including prescription medications, over-the-counter medications, and supplements.

Finally, realize that allergy medications can have variable efficacy in cats, just like they do in people. You and your veterinarian may need to experiment a bit, in order to find the best cat allergy medicine for your feline family member. If your cat’s signs cannot be controlled with medications, your veterinarian may recommend additional steps, such as allergy testing and hyposensitization treatments.

Allergies are managed, not cured and most cats will require lifelong treatment. Develop a good working relationship with your veterinarian and their staff, so you can work together to provide the best possible allergy relief for your cat.